To the Editor: In their study of job strain, Dr Aboa-Éboulé and colleagues1 concluded that high job strain after a myocardial infarction was associated with an increased risk for future coronary events. There are several important issues with this conclusion that we believe need to be considered.

First, this study was conducted in Canada. Because social, cultural,
and economic covariates influence job strain, the application of these results to other populations should be done with caution. With these types of cofactors, confounding may persist despite multivariate analysis adjusting for 26 variables. Second, the study design may be prone to volunteer bias, which would likely lead to preferential selection of patients with more extreme stress and coronary artery disease.